Magnesium is lightweight and is rich as a resource, and is therefore much highlighted as a weight-reducing material for electronic appliances, structural parts, etc. Above all, in case where applications to mobile structural parts such as rail cars, automobiles and others are investigated, the materials are required to have high strength and high ductility characteristics from the viewpoint of the safety and reliability in use thereof. For improving the characteristics of metallic materials, reduction in the scale (size) of the microstructure of matrix, or that is, so-called grain refining is well known. A fine particles dispersion strengthening method (of dispersing fine particles in a matrix) is also one method for improving the characteristics of metallic materials.
Recently, it has become specifically noted to use, as dispersion particles, a quasicrystal phase which does not have a configuration of recurring units of predetermined atomic arrangement, or that is, does not have translational regularity unlike ordinary crystal phase. The principal reason is because the quasicrystal particles well match with the crystal lattice of matrix and the lattices may strongly bond to each other, and therefore, the dispersion particles of the type could hardly be a nucleus or a starting point for destruction during plastic deformation. Regarding magnesium alloys, it is known that dispersion of quasicrystal particles therein brings about excellent mechanical characteristics, as shown in the following Patent References 1 to 5.
With that, for further performance advances, refining the magnesium matrix is tried.    Patent Reference 1: JP-A 2002-309332    Patent Reference 2: JP-A 2005-113234    Patent Reference 3: JP-A 2005-113235    Patent Reference 4: WO2008-16150    Patent Reference 5: JP-A 2009-084685